| 摘要 |
PURPOSE:To utilize load dispersion and sources effectively by dividing a redundancy internal communication line into a cluster controlling unit and a redundancy unit. CONSTITUTION:When both lines 71, 72 of the redundancy internal communication line 7 are normal, a cluster control unit 5 generalizes the inside of a cluster by communication using the line 71 to control message communication between an external station and each process control unit 4i in the cluster and monitors the state of each unit 4i. A redundancy unit 6 executes up-load of a data base of each unit 4i, state monitoring of each unit 4i and back-up operation for a defective unit out of units 4i by the communication using the line 72. Consequently, the communiation line 7 can be used by dividing it by the units 5, 6. |
